Files
sglang/test/registered/unit
laoyao0822 ec7e9fbc57 Avoid full-prompt embedding in CP MTP prefill
The CP draft shared-KV path only needs this rank's local draft tokens, but the previous compatibility path embedded the full prompt before CP-splitting. For long MTP/EAGLE prefill this recreates the large hidden activation that CP shared KV is trying to avoid.\n\nThis pads local draft input ids to the per-rank max token count recorded in NSA CP metadata, embeds the padded local tensor, then trims back to the true local length. That keeps rank shapes compatible while avoiding full-prompt embedding on every rank. Missing or stale metadata keeps the existing full-embedding fallback.\n\nConstraint: CP ranks can own uneven token counts, so the local embedding path needs a rank-uniform padded shape.\nRejected: Pad local ids to the full prompt length | this preserves compatibility but loses the intended memory reduction.\nConfidence: medium\nScope-risk: moderate\nDirective: Do not remove the full-embedding fallback unless all CP draft metadata producers guarantee max_rank_len for every prefill path.\nTested: g0034 container py_compile for utils.py and deepseek_nextn.py; g0034 container pytest -q test/registered/unit/layers/test_nsa_cp_utils.py => 25 passed, 5 warnings.\nNot-tested: Full distributed E2E with HiCache cache-hit MTP accept-length recovery.
2026-05-23 15:48:36 +08:00
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Unit Tests

Component-level tests that do not launch a server or load model weights. Tests can use CPU or GPU — the key criterion is no server process.

Quick Start

  1. Find the source file under python/sglang/srt/.
  2. Create the corresponding test here, mirroring the source tree:
    srt/mem_cache/radix_cache.py       →  unit/mem_cache/test_radix_cache.py
    srt/sampling/sampling_params.py    →  unit/sampling/test_sampling_params.py
    
  3. Register for CI at the top of the file (after imports, before test classes):
    from sglang.test.ci.ci_register import register_cpu_ci
    register_cpu_ci(est_time=5, suite="stage-a-test-cpu")
    # or: register_cuda_ci(est_time=10, suite="stage-b-test-1-gpu-small")
    
  4. Run locally:
    pytest test/registered/unit/ -v            # all unit tests
    pytest test/registered/unit/mem_cache/ -v  # one module
    
  5. Run with coverage:
    # summary
    pytest test/registered/unit/ --cov --cov-config=.coveragerc -v
    
    # PR incremental check (require ≥60% on changed lines)
    pytest test/registered/unit/ --cov --cov-config=.coveragerc --cov-report=xml
    diff-cover coverage.xml --compare-branch=origin/main --fail-under=60
    

Example

"""Unit tests for <module> — no server, no model loading."""

from sglang.test.ci.ci_register import register_cpu_ci

register_cpu_ci(est_time=5, suite="stage-a-test-cpu")

import unittest

from sglang.srt.<module> import TargetClass
from sglang.test.test_utils import CustomTestCase


class TestTargetClass(CustomTestCase):
    def test_basic_behavior(self):
        obj = TargetClass(...)
        self.assertEqual(obj.method(), expected)


if __name__ == "__main__":
    unittest.main()

Rules

  • No popen_launch_server() or Engine(...).
  • No model weight loading.
  • Use CustomTestCase (from sglang.test.test_utils, adds CI retry).
  • Use unittest.mock for dependencies that are expensive to construct.